A legislative committee has crafted a good compromise to lower dangerous pollution from outdoor wood boilers, an increasingly popular source of heat and hot water. The compromise is a mixture of federal rules and common sense that should offer relief in the short term and produce cleaner-burning stoves over the next several years.

The sale of outdoor wood boilers tripled between 2004 and 2005. As oil and natural gas prices continue to rise, the devices will continue to increase in popularity. At the same time, more than two dozen communities from Greenville to Wells have fielded complaints about the smoke the boilers emit.

The boilers don’t use catalytic emission control devices as most indoor wood stoves do. They also are built with short smoke stacks, which keeps smoke near the ground, and with big fire boxes, which allows owners to burn all sorts of things that wouldn’t fit into a wood stove. These problems are exacerbated because the units often are used in residential neighborhoods.

The average wood boiler emits more than 70 grams of particulate pollution per hour, more than 15 times the Environmental Protection Agency’s standard for indoor wood stoves. The most polluting units emit more than 300 grams per hour. Particulate pollution worsens asthma and is linked to lung cancer and other cardiorespiratory diseases.

The EPA recently developed voluntary standards for wood boiler emissions. Ten manufacturers agreed to sell boilers, beginning this spring, that emit no more than 0.6 pounds of particulate matter per million BTUs of heat input. The boilers must be tested by an accredited third-party laboratory to verify they meet this level. Models that do will carry a tag showing how its emissions compare with the EPA specifications.

In Maine, the Natural Resources Committee last week unanimously agreed to make the EPA standard mandatory beginning next April for new boilers in Maine. Following the EPA model, allowable emissions will drop to 0.32 pounds per BTU in 2010.

Instead of a moratorium on the sale or installation of wood boilers or a seasonal ban on their use, the committee also will direct the Department of Environmental Protection and manufacturers to visit and inspect boilers that are known to have been the source of complaints. While they are directed to look for remedies, the department should be required to report to the Legislature on how boilers were fixed to reduce emissions.

Along the same lines, the DEP is to seek the best ways to alleviate further problems from boilers already in place. This can be done through setbacks, stack height requirements or other means through new rules to be written by the DEP.

A revised bill, which currently is being drafted by the committee’s staff, also will put in place a system for residents to report problems and try to have them remedied, through town, and if needed, state officials.

These are straightforward ways to deal with the growing problem of wood boilers.